The Steel Beam Incident (鉄骨落下事件, Tekkotsu Rakka Jiken) was the pivotal event of the series, occurring some time in early October in the 20th Ward.
- Ken Kaneki - Victim
- Rize Kamishiro - Victim
- Souta - Perpetrator
- Akihiro Kanou - Surgeon
- Taguchi - Nurse and Collaborator
After their date, Rize Kamishiro tricked Ken Kaneki into escorting her down an isolated alleyway near a construction site. There, she revealed herself to be a ghoul and attacked him with the intention of devouring him. He was critically injured in the attack, but survived when steel beams dropped on Rize and crushed her.
The accident drew the attention of nearby pedestrians, who called for emergency services to help the victims. Kaneki and Rize would both be sent to Kanou General Hospital, where they became the patients of Dr. Akihiro Kanou. Reporting that the girl was already deceased, he transplanted Rize's kakuhou into Kaneki and converted him into an one-eyed ghoul. The unauthorized transplant drew considerable media attention, and Dr. Kanou faced heavy criticism for performing an organ transplant without permission from the families of his patients.
Itori hinted that someone had been seen at the construction site, and that Rize had actually been murdered. This drove Kaneki to seek the truth about the incident, looking for both Rize's past and Dr. Kanou for several months. He would eventually learn that Rize had survived, and was being exploited by Dr. Kanou as a donor for further ghoulification experiments.
During the Owl Suppression Operation, a critically-wounded Kaneki recalled having seen the Clown Souta at the scene of the accident. Four years later Kaneki confronts Souta and questions why he was targeted as a victim for the accident. Souta replies his real target was Rize herself so he could give her to Kanou because of his desire that she does not have children with another man. He further elaborates that Kaneki's involvement was a coincidence and not personal.